Trezor Safe 7 review: FOSS self-custody wallet adds Bluetooth and battery
Bitcoin Magazine reviews Trezor's Safe 7, a hardware wallet with a metal body, 20-word SLIP-39 backups and Bluetooth, and weighs its move away from strict air-gapped cold storage.
Key points
- The Safe 7 ships in multi-coin and Bitcoin-only firmware versions, and users can switch between them at will.
- It uses 20-word SLIP-39 backups, introduced by Trezor in 2019 with Shamir backup, offering the same 128 bits of entropy as 12-word seeds.
- The device adds Bluetooth, an internal LiFePO₄ battery and Qi2 wireless charging, features absent from earlier Trezor models.
- Trezor's shipping partner ShipMonk exposed 67,000 U.S. customer records, prompting an anonymous delivery service planned for the EU within weeks.
- Trezor draws entropy from four sources, including the Optiga and TROPIC01 secure elements, but does not yet accept user-generated entropy.
Bitcoin Magazine has reviewed the Trezor Safe 7, a self-custody hardware wallet that the outlet describes as a middle ground between hand-assembled air-gapped devices and closed-source products. The review says the Safe 7 feels like a modern iPhone, with a metal exterior, a screen reaching the device border and tactile feedback. Bitcoin Magazine reports that the device makes bitcoin feel like a physical thing in a way most other wallets do not.
Trezor sells the Safe 7 with two firmware stacks: a standard multi-coin version in black and green, and a Bitcoin-only orange model. Buyers can switch between the two regardless of the colour they order, according to the review. Bitcoin-only firmware is leaner, and Trezor's support articles say its advantages include fewer regular updates and a reduced risk of bugs or security issues.
Two firmware options
The Safe 7 uses 20-word SLIP-39 backups rather than the more common 12 or 24 words. Bitcoin Magazine explains that SLIP-39, introduced by Trezor in 2019 alongside Shamir backup, offers the same 128 bits of entropy as 12-word seeds but uses a curated word list. Shamir lets users split a backup into shards, so a two-of-three setup stored in separate locations survives the loss of any single shard. The scheme is supported by wallets such as Sparrow and Electrum, though adoption lags behind BIP-39.
The review highlights the user experience, including a press-and-hold approval that triggers vibration, flowing green lights and a mechanical sound before confirming a transaction. Buttons are larger than on the Model T, reducing PIN entry errors that can wipe a device. The Safe 7 also adds Bluetooth, an internal LiFePO₄ battery and Qi2 wireless charging, which Bitcoin Magazine says moves it closer to a high-security warm wallet than strict cold storage. Trezor encrypts data in transit with its Host Protocol.
Shamir and entropy
On entropy, the review says the Safe 7 draws on four sources, including a hardware TRNG in the STM32 microcontroller, the Optiga secure element and the TROPIC01 chip. Trezor does not currently allow user-generated entropy, and chief commercial officer Danny Sanders told Bitcoin Magazine the topic had been discussed a lot and was not a hard no, but that Trezor's larger user base cannot be asked to throw dice.
Bitcoin Magazine also covers a breach at Trezor's shipping partner ShipMonk, which exposed 67,000 U.S. customer records earlier this month. Trezor says most of those records should already have been deleted. Sanders said an anonymous delivery service will launch in the EU within weeks and expand to the US soon after. The review concludes that the Safe 7 is a serious evolution suited to multi-vendor multisig or daily use.